“SHIRATAKI (noodles made of devil's tongue)”, which is also referred to as “ITOKONNYAKU”, is a traditional Japanese food used in Japanese-style dishes such as ODEN (Japanese hotchpotch boiled in a kelp-based broth seasoned with soy sauce), SUKIYAKI (thin slices of beef cooked in a heavy iron pan with various vegetables and TOFU) and NIMONO (steamed food). SHIRATAKI is produced by adding an alkalinity coagulant such as calcium hydroxide to “KONNYAKU paste” which is prepared by dissolving grinded KONNYAKU potato and/or KONNYAKU powder in water, and subsequently boiling a stringy extrusion derived from said KONNYAKU paste to gelate it.
The SHIRATAKI is generally cooked together with other foods without seasoning and then eaten. It is inappropriate to eat SHIRATAKI like noodles without cooking it since uncooked SHIRATAKI have a texture like a rubber and no taste.
“TOFU (bean curd)” is a traditional Japanese food used in NIMONO and/or miso soup, and is produced by boiling soy milk, adding a coagulant to this boiling soy milk, and then coagulating it into a predetermined shape. TOFU has a soft and smooth texture, but TOFU is produced by charging it in a container or casing and it is thus difficult to produce TOFU in the form of elongated string-like noodles.
Japanese Laid-Open Patent Application 8-98661(1996) describes TOFU KONNYAKU characterized in that KONNYAKU (devil's tongue) and a bean curd ground product are mixed uniformly, the mixture is coagulated entirely by gel of KONNYAKU and the resulting TOFU KONNYAKU is porous due to air bubbles contained in it. The Japanese Patent Application also describes forming the TOFU KONNYAKU in a form such as that of SHIRATAKI, i.e. a stringy form.
Japanese Laid-Open Patent Application 8-98662(1996) describes a method for producing KONNYAKU characterized in adding water to KONNYAKU powder or grinded KONNYAKU potato and mixing it, preparing KONNYAKU paste by swelling the mixture, crumbling the KONNYAKU paste by a cutter, chopper or grater, subsequently adding and stirring an additional material(s) to this mixture, then adding a coagulant, followed by forming and heating. The Japanese Patent Application also describes forming the KONNYAKU in a stringy form.
This prior art provides foods having a taste and texture which are a combination of those of KONNYAKU and TOFU by coagulating the mixture of KONNYAKU paste and a bean curd ground product. That is, the foods are softer and tenderer than KONNYAKU and harder and tougher than TOFU, and have a porous texture in which air bubbles are contained in them and thus when these foods are boiled, gravy can penetrate within them to make them taste good.
In the method for producing TOFU KONNYAKU described in Japanese Laid-Open Patent Application 8-98662(1996), however, it is very difficult to uniformly mix the KONNYAKU paste with other material(s), because the KONNYAKU paste has high viscosity after preparing it. It is also necessary to crumble the KONNYAKU paste by a cutter, chopper or grater, after preparing and before mixing it with the bean curd ground product. Furthermore, in the production process which comprises treating the KONNYAKU paste, which is prepared by letting a mixture of water added to KONNYAKU powder or grinded KONNYAKU potato stand for not less than one hour to swell it, crumbling the KONNYAKU paste by a cutter, chopper or grater and then mixing it with an additional materials, it takes a long time to conduct the steps from mixing the materials to the end of production. In addition, this prior art has a problem in that the TOFU KONNYAKU breaks due to some air bubbles growing together because the TOFU KONNYAKU has a porous texture in which the air bubbles are produced when the bean curd ground product is mixed with the KONNYAKU paste and thus the TOFU KONNYAKU cannot be formed in the stringy form of a stably uniformed size.